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A load of hot air?

From
Steve Orchard

Abigail Beall writes that storing excess wind power as compressed air is “not such a bad idea after all” (1 November, p 50). It is one way of easing the peaks between electricity supply and demand, but by itself it isn’t a particularly efficient way of achieving it.

Compressing air requires a significant amount of energy and produces a significant amount of waste heat. Unless that heat is utilised at the time of compression, you will end up storing only a fraction of the energy put in. There will be further energy losses when the compressed air is released to regenerate electricity.

Using gravity to store energy, in the form of water pumped uphill, is probably a more efficient method.

This has been happening at Ffestiniog hydroelectric power station in north Wales since 1963, meaning the technology arrived in the UK 15 years earlier than suggested in your article.North Nibley, Gloucestershire, UK